The present invention relates to a method and a container for packaging a fluid under pressure that is intended to be dispensed in a paste, liquid or aerosol form, the fluid to be dispensed being put under pressure by means of a propellant. The invention relates to the situation in which for reasons of safety, quality or conformity of the fluid to be dispensed, the fluid to be dispensed must be prevented from coming into contact with the propellant both before and during use.
Various packaging means meeting these objectives have already been proposed, among which the one having recourse to neither internal mechanical devices nor expensive packaging means while being absolutely safe in its function will be recalled, that is, the means described in French Patent No. 2 229 241.
In the technique that is the subject of this patent, a fluid intended to be dispensed in the aforementioned form is packaged under pressure by introducing a flexible, gas-tight, hermetically sealed pouch, on the inside of which is a cartridge, also closed and filled with a propellant in the liquid phase into the outer envelope of the packaging container, opened at one of its ends, preferably prior to the introduction of the fluid to be dispensed; the free end of the container is plugged, the closed container thus constituted including a valve enabling at least the dispensing of the packed fluid; and after having filled the container with fluid to be dispensed, the opening of the cartridge and the passage of at least some of the propellant to the gaseous phase are effected, causing the propellant to spread into the entire internal free volume of the pouch, at a pressure suitable to assure the dispensing of the fluid around the pouch, from the valve with which the container is provided.
In a preferred embodiment, the opening of the cartridge is brought about by heating the container, filled with the fluid to be dispensed that surrounds the pouch, to a temperature sufficient to enable the opening of the cartridge under the influence of the increase in internal pressure of the propellant.
It is also stated that the opening of the cartridge can be accomplished by dissolving it, at the end of a period of time that can be determined in advance, in a solvent initially located in the flexible pouch.